Speed controller for a diesel engine

ABSTRACT

This invention relates to a speed controller for a diesel engine, said controller being arranged to be controlled normally by a pneumatic negative pressure controlled by a throttle valve operatively connected with an engine accelerator pedal or its equivalent means. The speed controller is characterized by the provision of a vacuum pump, a pressure controller and change-off valve means which are connected in such a way that upon reception of an instruction signal for control of the engine revolutions, said change-off valve means is/are brought into operation and the negative pressure created and delivered by said pump and modified by said pressure controller is used for the speed control purpose and in place of said negative pressure created at the throttle valve.

United States Patent Hirozawa [451 Sept. 26, 1972 [54] SPEED CONTROLLER FOR A DIESE 3,392,714 7/1968 Braun et al. 123/ 140 MC ENGINE Prima Examiner-Allan D. Herrmann 72 'y I l 'Memor gygy-9 H-iv'M-mvabapa Assistant Examiner- Randall Heald [.731 Assignee: Kabusilriliaisha, Kari- Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak YaJaPan i [22] Filed: Dec. 23, 1970 17] ABSTRACT is invention relates to a speed controller for a diesel [2l l Appl' No" 100938 engine, said controller being arranged to be controlled normally by a pneumatic negative pressure controlled [30) Foreign Application Priority Data by a throttle valve operatively connected with an en- Dec. 23, 1969 Japan ..44/103979 gine accele'rator pedal or its equivalent means' The speed controller is characterized by the provision [52] U.s. cl 12s/14o MP, 74/858, 192/.092 0f a vacuum pump, a pressur'comroller and Change- [51] im. ci Fozd 1/04 Off valve means which are Connected in Such a way [5s] Field of Search ..74/858 x, 875, 873; that upon reception 0f an instruction Signal for control 123 /140 Mp; 192/092 of the engine revolutions, said change-off valve means is/are brought into operation and the negative pres- 56] References Cited sure created and delivered by said pump and modified by said pressure controller is used for the speed con- UNITED STATES PATENTS trol purpose and in place of said negative pressure 2,446,711 8/1948 Mauory ..74/858 ftedtllfhme Valve- 2,702,029 2/l955 Burton ..123/140 MP 2,727,504 l2/l955 Peras ..123/140 MP 7 Claims, 1 Drawing Figure 1 SPEED CONTROLLER FOR A DIESEL ENGINE This invention relates to an improved speed controller for a diesel engine.

The object of the invention is to provide a speed controller'providing a broad possibility for automatic control of the fuel injection system for a diesel engine.

For the realization of said object, the speed control according to the invention is characterized by the features disclosed in the appended claims.

In this way, such a possibility is provided in a cornbined set of diesel engine with a conventional speed gear change unit, the fuel injection rate can be automatically controlled by the speed change signals. In this improved arrangement, the so-called racing phenomenon as frequently encountered in the speed change step caused by an interruption of the engine drive can effectively prevented.

Another possibilitiesreside, for instance, in the application of the speed controller to constant speed control devices, automatic steering devices and/or the like, for attaining more efficient and effective results,

These and further objects, features and advantages of the invention will become more apparent when read the following detailed description of the invention by reference to the accompanying drawing illustrative of a preferred sole embodiment of the invention.

The drawing is a schematic and illustrative general arrangement view of a preferred embodiment of the apparatus according to the invention destined for the control of revolutional speed of a diesel or compression ignition type internal combustion engine.

Referring now to the accompanying drawing, a preferred embodiment of the invention wherein the internal combustionv engine is combined with a regular speed change gearing of the synchronously engageable type and a clutch unit 'of the conventional design, will be described hereinafter in detail.

ln the drawing, numeral l 1 represents only schematilcally a conventionalv accelerator pedal which is pivotably mounted at l3on a floor pannel 12, only shown partially and in its section, of an automotive vehicle fitted with a diesel or compression ignition type internal combustion engine. l

At the top end of the pedal l1, a connecting rod 14 is pivotably connected with its one end, said rod extending through an opening 15 perforated through the board l2 and being linked at 18 to a bellcrank lever 17 which is pivotably mounted at 16 on the lower surface of said board l2.

The opposite end of lever 17 is linked at 20 to one end of an elongated connecting rod 19 only schematically shown by a single line, while the opposite end of said rod is linked to the lower end of an operating lever 23 the upper end of which is rigidly connected with a pivotably mounted pin 22a rigid with a throttle plate 22 constituting a main part of a conventional venturi unit 2l having a duct 121 leading to an air supply opening, not shown, of a diesel or compression ignition engine.

A conduit piping 24 is pneumatically connected with an opening 25 which is formed on thewall of said duct 121 of the venturi unit 2l, and arranged for cooperation with a duct 29 formed in a change-off valve member 26 rigid with a plunger 28 controlled by an electromagnetic solenoid 27, said duct 29 being arranged so as to cooperate with a stationary piping 30 leading to an inlet port 33 which is formed in the bottom wall of casing 32 of a fuel regulator 31.

A further and inclined duct 34 is formed laterally through valve member 26 and so designed and arranged thatupon energization of solenoid 27, pipings 30 and 35 are luidically connected with each other, the latter piping 35 leading a port 49 formed throughy a casing 46 of pressure control valve unit 44.

The interior space of casing 32 is divided into two chambers 80 and 82 by a diaphragm 36, the peripheral surface of the latter being rigidly attached to the inside wall of said casing. A fuel-adjusting rod 37 is rigidly attached 'at its one end with the diaphragm 36 at its center. Although the rod 37 is only shown partially, it is mechanically connected with a control rack, not shown, adapted for control of the fuel injection quantity for the engine, as known per se and in such a way that with the rod rightwardly shifted, the fuel injection quantity is increased correspondingly and vice versa. Although not shown, the right-hand chamber 80 of the unit 31 is kept in pneumatic communication with open atmosphere. On the contrary, the left-hand chamber 82 contains a back-up spring 38 for the diaphragm 36 and is, additionally, in kept in fluid communication with said piping 30 through port 33. Thus, the diaphragm 36 is subjected to a rightwardly acting urging force.

Numeral 39 represents a vacuum pump, only schematically represented, which is mechanically connected with the crankshaft, not shown, of the engine, through a chain, belt or the like conventional transmitting means. When driven, this pump 39 generates vacuum which is conveyed to a piping 40 leading to further pipings 42 and 43 yas shown through a junction 41.

Pressure regulator unit 44 comprises a pair of casing hand chamber 185, so as to resiliently urge the diaphragm valve assembly 47;50 towards left. The valve member 50 is so designed and arranged as to cooperate with the port 48 for control of the fluid passage rate thereat when the assembly is urged to move rightwards from the position shown and against the action of spring 51, as will be more fully described hereinafter. Casing part 45 is formed with port 52 which is kept in communication through a piping 53 with open atmosphere.

The upper extreme end of piping 43 is kept in mutually slidable contact of a slide valve member 54 which is rigid with a plunger 59 electromagnetically controlled by a solenoid 58 of clutch control changeoff valve member 154 which is shown in its clutch-off position. A spring 60 is inserted under pretension between a part of the chassis of an automotive vehicle, not shown. The solenoid 58, plunger 59, valve member 54, straight passage 57 and inclined passage 55 formed therethrough constitute in combination a change-off valve unit.

This change-off valve unit 154 is so designed and arranged that with the solenoid 58 energized, valve member 54 is shifted rightwards against the action of spring 60, piping 43 is brought into fluid communication through straight duct 57 with a piping 56.

Duct 55 is normally kept in fluid communication through a piping 83 with open atmosphere, on the one hand, and with a piping 56 leading to a chamber 84 of the interior space of a servo unit 6l comprising casing parts 63 and 64 rigidly coupled together.

Clutch master cylinder 62 is combined with said servo unit 6l comprising said casing parts63 and 64 and a diaphragm 65 vis at its peripheral zone fixedly gripped therebetween, said diaphragm being rigidly attached with a piston rod 66 having a piston 66 made rigid therewith. A spring 67 is inserted between the casing part 63and the diaphragm 65 by which the interior space of the casing 63; 64 is divided into two chambers 68 and 84. The piston 69 is slidably mounted within the interior space 7l of cylinder 62. Spring 67 urges the diaphragm 65 to movetowards right. The chamber 68 defined by diaphragm 65 and casing part 64v is kept always in fluid communication with open atmosphere, as hinted in the drawing.

The rod 66 passes through the end wall of clutch master cylinder 62 and connected rigidly with said piston 69. Piping 70 iiuidically connects the cylinder space 7l with the left-hand end of the interior space of a clutch release cylinder 72 mounting inturn a piston 73 slidably. A piston rod 74 is rigidly connected by its one end with said piston 73.

Numeral 75 represents a conventional release lever 75 adapted by its actuating upper end for on-off controlling a clutch 78 through a release bearing 76 and a diaphragm spring 77. In the preferred embodiment shown, several related parts with the clutch are so designed and arranged that when piston 73 is moved rightwards, clutch 78,is brought into its interrupted position and vice versa. The clutch is mechanically connected with a conventional synchronously engageable speed change gearing 79 having four forward drive steps and a rear drive step. This kind of gearing as at 79 is highly conventional and popular so that it has been shown only in a highly simplified and schematic manner.

Ends denoted A and B of the solenoids 27 and 58 are electrically connected to conventional switch means fitted on a conventional automotive shift lever, although not shown, in such a way that when a vehicle driver grips the operating knob of the shift bar, said switch means is/are brought into lclosed position by being subject to the manually gripping pressure. In an alternative arrangement, although again not shown, said ends A and B are connected to switch means which is/are operable with electrical signals for actuation or control of an automotive speed change mechanism in response to occasional vehicle speed or throttle valve opening degree.

lt should be noted that slide valves 26 and 54 are enclosed as conventionally in respective housings, although these housings have been omitted only for simplicity.

The operation of the mechanism so far shown and described is as follows:

When the vehicle operator manipulates accelerator pedal 1l to close and open to a certain desired degree and the vehicle is running at a certain travelling speed, a negative air pressure created as conventionally below the throttle or butterfly valve 22 of venturi unit 2l will be conveyed through outlet opening 25, piping 24, passage 29 in change-off valve 26 and further piping 30 to fuel adjuster unit 31 or morespecifically into the left-hand chamber 82, thus creating an appreciable air pressure difference across diaphragm 36, so as to urge the diaphragm 36 together with'rod 37 towards left for control the fuel injection quantity.

When the driven actuate the shift lever, not shown, the switch means mountedtherein (or thereon) is automatically closed so that solenoids 27 and 58 are energized.

With energization of solenoid 58, change-off valve 54 is moved rightwards against the action of spring 60 and the straight passage 57 is brought into fluid communication with pipings 43 and 56 and the duct 83 communication with open atmosphere is interrupted from communication with piping 56.

Thus, vacuum created at the pump 39 will be conveyed therefrom through pipings 40 and 43 and passage 57 and further piping 56 to the left-hand chamber 84 of servo unit 61, thereby the piston 69 together with its rod 66 and diaphragm 65 being moved towards left. In this way, the piston 73 is moved in the right-hand direction under the influence of the compressed hydraulic medium such as oil filled in the cylinder chamberl 7l, piping 70 and the left-hand chamber of clutch release cylinder unit 72. ln this way, clutch release lever 75 will be actuated to rotate in counter clockwise direction for bringing theclutch 78 into its interrupted position.

With simultaneous energization of solenoid 27, change-off valve 26 is attracted against the action of spring 81 so that the inclined passage 34 is brought into fluid communication with pipings 30 and 35, while the piping 24 is brought into its interrupted position.

Thus, the vacuum created by pump 39 is conveyed through pipings 40 and 42, port 48, chamber 185, port 49, piping 35, inclined passage 34and piping 30 into the left-hand chamber 82 of fuel adjuster unit 3l. Pneumatic pressure differential thus created across diaphragm 36, the latter together with rod 37 is urged to move leftwards for reducing the fuel injection quantity.

Pressure control valve unit 44 is so designed and arranged that by presetting the spring pressure 5l, a properly controlled vacuum pressure is conveyed from the vacuum pump 39 to'the vacuum chamber 82 of unit 31.

It will thus be seen from the foregoing that the revolutional speed of a compression ignition engine can be automatically controlled to a desired degree with use of the aforementioned mechanism. As an example, and as referred to hereinbefore, when the engine is combined with a conventional speed change gearing of the synchronous engageable type and a speed changer fitted with clutch means, the fuel delivery rate of a fuel injection pump for the engine can be controlled in the delivery-reducing sense and responsive to a clutch actuation signal generated at the speed change operation. A merit thereby realized is such that unpleasant -racing problem as appearing upon continued accelerator pedal depression even after a clutch interruption caused by an automatic speed change operation can be settled in an efficient manner. As a further example, an undue increase of the engine revolution caused by a mal-manipulation of the shift lever which is normally in operative connection with the clutch disengaging means in a semi-automatic speed changer can be effectively avoided.

The embodiment of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. Speed controller for a compression ignition engine, comprising a throttle valve means for controlling air flow into said engine, means for sensing negative pneumatic pressure created with said engine in response to movement of an accelerator pedal, rst conduit means for conveying said negative pressure to an engine speed control means controlled by said negative pressure, a pump means operatively connected with said engine for generating' negative pneumatic pressure, second conduit means for conveying said pump generated negative pressure to said engine speed control means, a change-over valve means connected in said first and second conduit means and adapted for interrupting said second conduit means during a regular travelling period of a vehicle driven by said engine and interrupting said first conduit means in response to an instruction signal for control of the engine speed.

2. Speed controller for a compression ignition engine, comprising a throttle valve means for controlling air flow into said engine, means for sensing negative pneumatic pressure created within said engine in response to actuating movement of an accelerator pedal, a vacuum pump adapted for generation of negative pneumatic pressure and being driven by said engine, an engine speed control means comprises two chambers defined by a diaphragm means arranged therebetween, a rod connected rigidly with said diaphragm means and adapted for control of engine speed in response to movement of said diaphragm, and a return spring abutting against said diaphragm, first conduit means adapted for conveying said negative pressure crested within said engine to one of said two chambers, second conduit means for conveying said negative pressure generated by said pump to said one of the two chambers, a pressure regulator valve means connected in said second conduit means, and a changeover valve adapted for interruption of said first conduit means upon reception of an instruction signal for the control of revolutions of said engine.

3. Speed controller as claimed in claim 2, wherein the second of said chambers is kept in pneumatic communication with open atmosphere.

4. Speed controller as claimed in claim 2, wherein said change-over valve includes a biasing spring and is made rigid with a solenoid and a plunger, said solenoid being electrically connected with switch means attached to an automotive shift lever for being energized electromagnetically upon closure of said switch means.

5. Speed controller as claimed in claim 2, wherein said pressure regulator valve comprises a diaphragm arranged between two chambers, a valve made rigid with said diaphragm, and a spring biasing against said dia ra m, one o said tw c a bers of s id ress re regg atogr valve being kept in uitril communication wlith open atmosphere.

6. Speed controller as claimed in claim 2, further comprising third conduit means adapted for establish# ing fluid communication between said vacuum pump and servo means of a clutch master cylinder assembly, the clutch master cylinder-servo means comprising a diaphragm defining two chambers, a rod connected to said diaphragm, a spring, and a piston, and further comprising fourth conduit means adapted for communication of said clutch master cylinder assembly with a clutch release assembly comprising a cylinder, a piston and a rod, a clutch means controlled by said rod of the clutch release assembly, and a clutch control changeover valve connected in said third conduit, said clutch control change-over valve being adapted for interrupting said third conduit means upon reception of said instruction signal for controlling the speed of said engine on and for introducing atmospheric pressure to one chamber of said servo means.

7. Speed controller as claimed in claim 6, wherein said clutch control change-over valve is biased by a spring, and is made rigid with a solenoid and a plunger, said solenoid being controlled in response to movement of a shift lever. 

1. Speed controller for a compression ignition engine, comprising a throttle valve means for controlling air flow into said engine, means for sensing negative pneumatic pressure created with said engine in response to movement of an accelerator pedal, first conduit means for conveying said negative pressure to an engine speed control means controlled by said negative pressure, a pump means operatively connected with said engine for generating negative pneumatic pressure, second conduit means for conveying said pump generated negative pressure to said engine speed control means, a change-over valve means connected in said first and second conduit means and adapted for interrupting said second conduit means during a regular travelling period of a vehicle driven by said engine and interrupting said first conduit means in response to an instruction signal for control of the engine speed.
 2. Speed controller for a compression ignition engine, comprising a throttle valve means for controlling Air flow into said engine, means for sensing negative pneumatic pressure created within said engine in response to actuating movement of an accelerator pedal, a vacuum pump adapted for generation of negative pneumatic pressure and being driven by said engine, an engine speed control means comprises two chambers defined by a diaphragm means arranged therebetween, a rod connected rigidly with said diaphragm means and adapted for control of engine speed in response to movement of said diaphragm, and a return spring abutting against said diaphragm, first conduit means adapted for conveying said negative pressure crested within said engine to one of said two chambers, second conduit means for conveying said negative pressure generated by said pump to said one of the two chambers, a pressure regulator valve means connected in said second conduit means, and a change-over valve adapted for interruption of said first conduit means upon reception of an instruction signal for the control of revolutions of said engine.
 3. Speed controller as claimed in claim 2, wherein the second of said chambers is kept in pneumatic communication with open atmosphere.
 4. Speed controller as claimed in claim 2, wherein said change-over valve includes a biasing spring and is made rigid with a solenoid and a plunger, said solenoid being electrically connected with switch means attached to an automotive shift lever for being energized electromagnetically upon closure of said switch means.
 5. Speed controller as claimed in claim 2, wherein said pressure regulator valve comprises a diaphragm arranged between two chambers, a valve made rigid with said diaphragm, and a spring biasing against said diaphragm, one of said two chambers of said pressure regulator valve being kept in fluid communication with open atmosphere.
 6. Speed controller as claimed in claim 2, further comprising third conduit means adapted for establishing fluid communication between said vacuum pump and servo means of a clutch master cylinder assembly, the clutch master cylinder-servo means comprising a diaphragm defining two chambers, a rod connected to said diaphragm, a spring, and a piston, and further comprising fourth conduit means adapted for communication of said clutch master cylinder assembly with a clutch release assembly comprising a cylinder, a piston and a rod, a clutch means controlled by said rod of the clutch release assembly, and a clutch control change-over valve connected in said third conduit, said clutch control change-over valve being adapted for interrupting said third conduit means upon reception of said instruction signal for controlling the speed of said engine on and for introducing atmospheric pressure to one chamber of said servo means.
 7. Speed controller as claimed in claim 6, wherein said clutch control change-over valve is biased by a spring, and is made rigid with a solenoid and a plunger, said solenoid being controlled in response to movement of a shift lever. 